Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS8039300 B2
Publication typeGrant
Application numberUS 12/954,160
Publication dateOct 18, 2011
Filing dateNov 24, 2010
Priority dateAug 15, 2005
Also published asCN101288187A, CN101288187B, EP1929556A1, EP1929556B1, EP2429007A2, EP2429007A3, US7521705, US7863595, US8476613, US20070034848, US20090179188, US20110070714, US20120018694, WO2007021913A1
Publication number12954160, 954160, US 8039300 B2, US 8039300B2, US-B2-8039300, US8039300 B2, US8039300B2
InventorsJun Liu
Original AssigneeMicron Technology, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Reproducible resistance variable insulating memory devices and methods for forming same
US 8039300 B2
Abstract
The present invention relates to the use of a shaped bottom electrode in a resistance variable memory device. The shaped bottom electrode ensures that the thickness of the insulating material at the tip of the bottom electrode is thinnest, creating the largest electric field at the tip of the bottom electrode. The arrangement of electrodes and the structure of the memory element makes it possible to create conduction paths with stable, consistent and reproducible switching and memory properties in the memory device.
Images(9)
Previous page
Next page
Claims(20)
1. A method of forming a memory element, the method comprising:
forming a first electrode such that a first end of the first electrode is larger than a second end of the first electrode;
forming a resistance variable insulating layer over said first electrode; and
forming a second electrode, wherein said resistance variable insulating layer is formed between said first and second electrodes,
wherein forming the first electrode comprises depositing a conductive material and rotating a substrate while depositing the conductive material an angle less than 75 degrees with respect to a top surface of the substrate.
2. The method according to claim 1, wherein forming the first electrode comprises forming the first electrode having a cone-like shape.
3. The method according to claim 1, wherein the conductive material is deposited in a single direction, such that the conductive material forms a cone-like structure on the substrate.
4. The method according to claim 1, wherein said first electrode is formed from a material selected from the group consisting of platinum, titanium, gold, and SrRuO3.
5. The method according to claim 1, wherein said resistance variable insulating layer is formed from doped or undoped BaTiO3, SrTiO3 or SrZrO3.
6. The method according to claim 1, wherein said resistance variable insulating layer is selected from the group consisting of Pr0.7Ca0.3MnO3, Nb2O5, TiO2, TaO5, and NiO.
7. The method according to claim 5, wherein said resistance variable insulating layer is formed by pulsed laser deposition, physical vapor deposition, sputtering, or chemical vapor deposition.
8. The method of claim 1, further comprising:
forming a first material layer over a substrate;
forming a second material layer over the substrate;
forming a first opening within the first and second material layers, wherein forming the first electrode comprises depositing the conductive material through the first opening, the conductive material being deposited in a single direction, such that the conductive material forms a cone-like structure on the substrate.
9. A method of forming a memory element, the method comprising:
forming a dielectric layer over a substrate;
forming an opening within said dielectric layer;
depositing a conductive material in said opening by rotating the substrate while depositing the conductive material, the conductive material being deposited in a single angled direction, such that the conductive material forms a cone-like structure on the substrate, the cone-like structure being a first electrode;
forming a resistance variable insulating layer in the opening; and
forming a second electrode over the resistance variable insulating layer,
wherein the conductive material is deposited at an angle less than 75 degrees with respect to a top surface of the substrate.
10. The method according to claim 9, wherein said first electrode is formed from a material selected from the group consisting of platinum, titanium, gold, and SrRuO3.
11. The method according to claim 9, wherein said resistance variable insulating layer is formed from doped or undoped BaTiO3, SrTiO3 or SrZrO3.
12. The method according to claim 11, wherein said resistance variable insulating layer is formed by pulsed laser deposition, physical vapor deposition, sputtering, or chemical vapor deposition.
13. The method according to claim 9, wherein said resistance variable insulating layer is selected from the group consisting of Pr0.7Ca0.3MnO3, Nb2O5, TiO2, TaO5, and NiO.
14. The method according to claim 9, further comprising planarizing said resistance variable insulating layer prior to forming said second electrode.
15. A method of forming a memory element, the method comprising:
forming a dielectric layer over a substrate;
forming a first opening within said dielectric layer;
widening a portion of said first opening within said dielectric layer to form a second opening;
depositing a conductive material through the first and second openings;
rotating the substrate while depositing the conductive material, the conductive material being deposited in a single angled direction, such that the conductive material forms a cone-like structure on the substrate, the cone-like structure being a first electrode;
forming a resistance variable insulating layer in the first and second openings; and
forming a second electrode over resistance variable insulating layer,
wherein the conductive material is deposited at an angle less than 75 degrees with respect to a top surface of the substrate.
16. The method according to claim 15, wherein said first electrode is formed from a material selected from the group consisting of platinum, titanium, gold, and SrRuO3.
17. The method according to claim 15, wherein said resistance variable insulating layer is formed from doped or undoped BaTiO3, SrTiO3 or SrZrO3.
18. The method according to claim 17, wherein said resistance variable insulating layer is formed by pulsed laser deposition, physical vapor deposition, sputtering, or chemical vapor deposition.
19. The method according to claim 15, wherein said resistance variable insulating layer is selected from the group consisting of Pr0.7Ca0.3MnO3, Nb2O5, TiO2, TaO5, and NiO.
20. The method according to claim 15, further comprising planarizing said resistance variable insulating layer prior to forming said second electrode.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 12/407,510, filed on Mar. 19, 2009, now U.S. Pat. No. 7,863,595, which is a continuation of U.S. patent application Ser. No. 11/203,141, filed Aug. 15, 2005, now U.S. Pat. No. 7,521,705, the subject matter of which are incorporated in their entirety by reference herein.

FIELD OF THE INVENTION

The invention relates to the field of random access memory (RAM) devices formed using a resistance variable material, and in particular to an improved structure for, and a method of manufacturing, a resistance variable memory element.

BACKGROUND OF THE INVENTION

Resistance variable memory is a RAM that has electrical resistance characteristics that can be changed by external influences. The basic component of a resistance variable memory cell is a variable resistor. The variable resistor can be programmed to have high resistance or low resistance (in two-state memory circuits), or any intermediate resistance value (in multi-state memory circuits). The different resistance values of the resistance variable memory cell represent the information stored in the resistance variable memory circuit. The advantages of resistance variable memory are the simplicity of the circuit, leading to smaller devices, the non-volatile characteristic of the memory cell, and the stability of the memory states.

FIG. 1 shows a cross-section of a conventional resistance variable memory device. This resistance variable memory device is a Type GRAD (one resistor, one diode) memory device. It includes a word line (N type region) 102 in substrate 100, a plurality of P+ regions 104 and N+ regions 106, wherein word line 102 and P+ region 104 constitute a diode. A dielectric layer 114 is formed over substrate 100. A plurality of memory units 107 are set in dielectric layer 114, wherein each memory unit 107 includes a flat plate bottom electrode 108, a flat plate top electrode 110, and a resistive film 112, which may be formed of one or more layers, between the flat plate bottom electrode 108 and the flat plate top electrode 110. Word line contact via 116 is formed in dielectric layer 114. One end of word line contact via 116 is electrically connected to N+ region 106; the other end is electrically connected to a conducting line 120 on the surface of dielectric layer 114 so that the word line 102 can electrically connect with external circuits. Furthermore, there is a bit line 118 formed on dielectric layer 114 for electrically connecting with top electrode 110 of the memory unit 107.

A second example of a conventional resistance variable memory device is a Type 1R1T (one resistor one transistor) memory device illustrated in FIG. 2. This device includes a plurality of N+ regions 202 and 204 in substrate 200. A dielectric layer 220 is formed over substrate 200. Dielectric layer 220 includes a plurality of memory units 207, a plurality of gate structures (word lines) 212 and a plurality of contact vias 214 and 216. Each memory unit includes a flat plate bottom electrode 206, a flat plate top electrode 208 and a resistive film 210; which may be formed of one or more material layers, each memory unit is set on the surface of a respective N+ region. Gate structure 212 and N+ regions 202 and 204 constitute a transistor. Contact vias 214 and 216 are electrically connected to the gate structure 212 and the common line 204, respectively, so that the gate structure 212 and the common line 204 can connect with the external circuits. Furthermore, there is a bit line 218 formed on dielectric layer 220 for electrically connecting with the flat plate top electrode 208 of the memory unit 207.

Unfortunately, the metal-insulator-metal (MBA) structure with a resistive film or insulting oxide sandwiched between two flat metallic electrode plates as disclosed in FIGS. 1 and 2 does not provide stable and reproducible switching and does not provide memory properties in a controlled manner, as the conduction path between the elements can occur anywhere in the resistive film or insulating oxide between the top and bottom electrodes. The random and unpredictable conduction path between the elements is believed to be created by random and unpredictable defect sites in the deposited film.

There is needed, therefore, an alternative apparatus for improving and controlling the conduction path between the electrodes in a resistance variable memory device to form large arrays of memory devices based on the resistance switching phenomenon.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to the use of a shaped bottom electrode in a resistance variable memory device. The shaped bottom electrode ensures that the thickness of the insulating material at the tip of the bottom electrode is thinnest, therefore creating the largest electric field at the tip of the bottom electrode. The small curvature of the electrode tip also enhances the local electric field. The arrangement of electrodes and the structure of the memory element makes it possible to create conduction paths with stable, consistent and reproducible switching and memory properties in the memory device.

Additional advantages and features of the present invention will be apparent from the following detailed description and drawings which illustrate preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-section of a conventional resistance random access memory device.

FIG. 2 shows a cross-section of another conventional resistance random access memory device.

FIG. 3 illustrates a partial cross-section of a memory device in accordance with an exemplary embodiment of the present invention.

FIG. 4 illustrates a partial cross-section of a memory device in accordance with an second exemplary embodiment of the present invention.

FIG. 5 illustrates a partial cross-section of a memory device in accordance with a third exemplary embodiment of the present invention.

FIG. 6 illustrates a cross-sectional view of a semiconductor wafer undergoing the process of forming a memory device according to an exemplary embodiment of the present invention.

FIG. 7 illustrates the semiconductor of FIG. 6 at a stage of processing subsequent to that shown in FIG. 6.

FIG. 8 illustrates the semiconductor of FIG. 6 at a stage of processing subsequent to that shown in FIG. 7.

FIG. 9 illustrates the semiconductor wafer of FIG. 6 at a stage of processing subsequent to that shown in FIG. 8.

FIG. 10 illustrates the semiconductor wafer of FIG. 6 at a stage of processing subsequent to that shown in FIG. 9.

FIG. 11 illustrates the semiconductor wafer of FIG. 6 at a stage of processing subsequent to that shown in FIG. 10.

FIG. 12 illustrates a cross-sectional view of a semiconductor wafer undergoing a second process for forming a memory device according to an exemplary embodiment of the present invention.

FIG. 13 illustrates the semiconductor of FIG. 12 at a stage of processing subsequent to that shown in FIG. 12.

FIG. 14 illustrates a cross-sectional view of a semiconductor wafer undergoing the process of forming a memory device according to an exemplary embodiment of a second embodiment of the present invention.

FIG. 15 illustrates the semiconductor of FIG. 14 at a stage of processing subsequent to that shown in FIG. 14.

FIG. 16 illustrates the semiconductor of FIG. 14 at a stage of processing subsequent to that shown in FIG. 15.

FIG. 17 illustrates a processor-based system having a memory element formed according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and show by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized, and that structural, logical, and electrical changes may be made without departing from the spirit and scope of the present invention. The progression of processing steps described is exemplary of embodiments of the invention; however, the sequence of steps is not limited to that set forth herein and may be changed as is known in the art, with the exception of steps necessarily occurring in a certain order.

The term “substrate” used in the following description may include any supporting structure including, but not limited to, a plastic, ceramic, semiconductor, or other substrate that has an exposed substrate surface. A semiconductor substrate should be understood to include silicon, silicon-on-insulator (SOI), silicon-on-sapphire (SOS), doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor material structures. When reference is made to a semiconductor substrate or wafer in the following description, previous process steps may have been utilized to form regions or junctions in or over the base semiconductor or foundation.

The invention will now be explained with reference to the figures, which illustrate exemplary embodiments and where like reference numbers indicate like features.

A memory device 301 according to an embodiment of the invention is schematically illustrated in FIG. 3. The device 301 includes a shaped bottom electrode 308, a top electrode 310, a dielectric layer 314, and a resistance variable insulating material 312 between the shaped bottom electrode 308 and the top electrode 310. In a preferred embodiment of the invention, the resistance variable insulating material 312 is formed from resistance-reversible materials such as colossal magnet resistive thin films, such as, for example a PCMO thin film (i.e., Pr0.7Ca0.3MnO3); oxidation films having Perovskite structure, such as, for example, doped or undoped BaTiO3, SrTiO3 or SrZrO3; or an oxidation film such as, for example, Nb2O5, TiO2, TaO5, and NiO. Preferably the resistance variable insulating material 312 is SrTiO3. The shaped bottom electrode 308 and the top electrode 310 may be formed from a metal such as, for example, platinum, titanium or gold, or other suitable materials such as, for example, SrRuO3.

Reference is now made to FIG. 4. FIG. 4 is similar to FIG. 3 and illustrates a memory device 303 where the resistance variable insulating material 312 has been planarized before the top electrode 310 has been formed over the substrate 300.

Reference is now made to FIG. 5. FIG. 5 is similar to FIGS. 3 and 4 and illustrates a memory device 304 according to a third embodiment of the present invention where the bottom electrode 308 is formed over a conductive plug 322. As discussed above with FIG. 3, resistance variable insulating material 312 has been planarized before the top electrode 310 has been formed over the substrate 300. It should be understood that the resistance variable insulating material 312 may simply deposited and then have the top electrode 310 formed over the resistance variable insulating material 312, as discussed above with reference to FIG. 3.

FIGS. 6-11 depict the formation of the memory device 301 according to an exemplary embodiment of the invention. No particular order is required for any of the actions described herein, except for those logically requiring the results of prior actions. Accordingly, while the actions below are described as being performed in a general order, the order is exemplary only and can be altered if desired.

FIG. 6 illustrates a dielectric layer 314 formed over the substrate 300. The dielectric layer 314 may be formed by any known deposition methods, such as sputtering by chemical vapor deposition (CVD), plasma enhanced CVD (PECVD) or physical vapor deposition (PVD). The dielectric layer 314 may be formed of a conventional insulating oxide, such as silicon oxide (SiO2), a silicon nitride (Si3N4); a low dielectric constant material; among others.

A mask 316 is formed over the dielectric layer 314. In the illustrated embodiment, the mask 316 is a photoresist mask; the mask 316, however, could instead be any other suitable material such as, for example, a metal. An opening 313 extending to the substrate 300 is formed in the dielectric layer 314 and mask 316. The opening 313 may be formed by known methods in the art, for example, by a conventional patterning and etching process. Preferably, the opening 313 is formed by a dry etch via process to have substantially vertical sidewalls.

As shown in FIG. 7, a portion of the opening 313 is widened to form an opening 315 within the dielectric layer 314. The opening 315 extends under the mask 316, such that the opening 313 through the mask 316 is smaller than the opening 315 through the dielectric layer 314. Preferably, the opening 315 is formed using a wet etch process.

FIG. 8 depicts the formation of the shaped bottom electrode 308. A conductive material is deposited on the mask 316 and through the openings 313, 315 onto the substrate 300 to form a cone-like shaped bottom electrode 308 and a conductive layer 341 over the mask 316. The shaped bottom electrode 308 may comprise any conductive material, for example, platinum, titanium or gold, or other suitable materials such as, for example, SrRuO3. The conductive material is deposited by a physical vapor deposition (PVD) process, such as evaporation or collimated sputtering, but any suitable technique may be used. As indicated by arrow 351, the substrate 300 is rotated during deposition of the conductive material. Additionally, as indicated by arrows 350, the conductive material is deposited in a single direction. Preferably, as shown in FIG. 8 by the angle of the arrows 350, the conductive material is deposited at an angle less than approximately 75 degrees with respect to the top surface of the substrate 300, but the conductive material can also deposited at an angle of approximately 75 degrees if desired.

By forming the shaped bottom electrode 308 using a PVD process, the seams or gaps that occur when an electrode is formed in the conventional chemical vapor deposition (CVD) plug process can be avoided. Additionally, PVD deposited material tends to have a smoother surface than CVD deposited material. Accordingly the shaped bottom electrode 308 may have a smoother surface than conventional electrodes.

The conductive layer 341 and the mask 316 are removed, as illustrated in FIG. 9. This can be accomplished by any suitable technique. For example, a chemical mechanical polish (CMP) step can be conducted or a solvent lift-off process may be used according to known techniques.

Referring to FIG. 10, a resistance variable insulating material layer 312 is formed within the opening 315 and surrounding the shaped bottom electrode 308. The resistance variable insulating material layer 312 is formed from resistance-reversible materials such as colossal magnet resistive thin films, such as, for example a PCMO thin film (i.e., Pr0.7Ca0.3MnO3); oxidation films having Perovskite structure, such as, for example, doped or undoped BaTiO3, SrTiO3 or SrZrO3; or an oxidation film such as, for example, Nb2O5, TiO2, TaO5, and NiO. Preferably the resistance variable insulating material 312 is SrTiO3. The resistance variable insulating material 312 is formed by known methods, such as, for example, pulsed laser deposition (PLD), PVD, sputtering, or CVD.

Referring to FIG. 11, a second electrode 310 is formed over the resistance variable insulating material layer 312. The second electrode 310 may comprise any electrically conductive material, for example, platinum, titanium or gold, or other suitable materials such as, for example, SrRuO3.

Conventional processing steps can then be carried out to electrically couple the memory device 301 to various circuits of a memory array.

FIGS. 12-13 illustrate another exemplary embodiment for forming the memory element 301 according to the invention. The embodiment illustrated in FIGS. 12-13 is similar to that described in FIGS. 6-11, except that the second opening 315 (FIG. 7) need not be formed.

As shown in FIG. 12, a mask 316, which may be a photoresist mask, is applied over dielectric layer 314 and substrate 300. An opening 313 extending to the substrate 300 is formed in the dielectric layer 314 and mask 316.

The shaped bottom electrode 308 can be formed as described above in connection with FIG. 8. A conductive material is deposited over the mask 316 and through the opening 313 onto the substrate 300 to form the shaped bottom electrode 308 and a conductive layer 341 over the mask 316 as illustrated in FIG. 13. As indicated by arrow 351, the substrate 300 is rotated during deposition of the conductive material. Additionally, as indicated by arrows 350, the conductive material is deposited in a single direction. Preferably, as shown in FIG. 13 by the angle of arrows 50, the conductive material is deposited at an angle less than approximately 75 degrees with respect to the top surface of the substrate 300, but the conductive material can also deposited at an angle less of approximately 75 degrees.

The memory device 301 is then processed as discussed above with reference to FIGS. 9-11. Conventional processing steps can then be carried out to electrically couple the memory device 301 to various circuits of a memory array.

FIGS. 14-16 depict the formation of the memory device 303 according to a second exemplary embodiment of the invention. FIG. 14 illustrates memory device which is processed as set forth above with reference to FIG. 6-10 or 12-13.

A CMP step is conducted to planarize the resistance variable insulating material layer 312 to achieve the structure shown in FIG. 15. A second electrode 310 is formed over the resistance variable insulating material layer 312 as illustrated in FIG. 16. As set forth above, the second electrode 310 may comprise any electrically conductive material, for example, platinum, titanium or gold, or other suitable materials such as, for example, SrRuO3. Conventional processing steps can then be carried out to electrically couple the memory device 301 to various circuits of a memory array.

The embodiments described above refer to the formation of only a few possible resistance variable memory element structures (e.g., resistance variable memory devices) in accordance with the invention, which may be part of a memory array. It must be understood, however, that the invention contemplates the formation of other memory structures within the spirit of the invention, which can be fabricated as a memory array and operated with memory element access circuits.

FIG. 17 illustrates a processor system 700 which includes a memory circuit 748, e.g., a memory device, which employs resistance variable memory elements (e.g., elements 301 and/or 303 (FIGS. 3 and 4, respectively)) according to the invention. The processor system 700, which can be, for example, a computer system, generally comprises a central processing unit (CPU) 744, such as a microprocessor, a digital signal processor, or other programmable digital logic devices, which communicates with an input/output (I/O) device 746 over a bus 752. The memory circuit 748 communicates with the CPU 744 over bus 752 typically through a memory controller.

In the case of a computer system, the processor system 700 may include peripheral devices such as a floppy disk drive 754 and a compact disc (CD) ROM drive 756, which also communicate with CPU 744 over the bus 752. Memory circuit 748 is preferably constructed as an integrated circuit, which includes one or more resistance variable memory elements, e.g., elements 200 and/or 600. If desired, the memory circuit 748 may be combined with the processor, for example CPU 744, in a single integrated circuit.

While the invention has been described in detail in connection with exemplary embodiments known at the time, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US5292717Jan 21, 1992Mar 8, 1994Siemens AktiengesellschaftMethod for the production of a structured composite with high-temperature superconductor material
US5804908Feb 21, 1997Sep 8, 1998Nec CorporationEnhancement in bonding strength in field emission electron source
US6849891Dec 8, 2003Feb 1, 2005Sharp Laboratories Of America, Inc.RRAM memory cell electrodes
US20010010837Dec 1, 2000Aug 2, 2001Kuniaki HoriePreparing an ultrafine particle dispersion liquid containing ultrafine metal particles, and dispersing the particles into an organic solvent, applying the dispersion on the substrate surface, drying and heating to join the metal or compound
US20010015879 *Dec 22, 1998Aug 23, 2001David J. BenardMethod for interrupting an electrical circuit
US20010050218Feb 12, 2001Dec 13, 2001University Of Central FloridaMetal oxide gels; rotating fluidized beds
US20020000296Jul 25, 2001Jan 3, 2002Sharp Kabushiki KaishaMethod of manufacturing color electroluminescent display apparatus and method of bonding light-transmitting substrates
US20020033378Jul 30, 2001Mar 21, 2002Ngk Spark Plug Co., Ltd.Printed wiring substrate and method for fabricating the same
US20020037647Sep 5, 2001Mar 28, 2002Hwang Jeng H.Heating; plasma etching
US20020067317Oct 17, 2001Jun 6, 2002Murata Manufacturing Co., Ltd.Composite dielectric molded product and lens antenna using the same
US20020067917Nov 13, 2001Jun 6, 2002Japan Pionics Co., Ltd.Vaporizer and apparatus for vaporizing and supplying
US20020072006Jul 26, 2001Jun 13, 2002Yuichi MizooToner, image-forming method and process cartridge
US20020106313Feb 1, 2001Aug 8, 2002University Of Central FloridaConverting the target pollutant that passes through the catalytic media to a selected level of destruction and removal efficiency (DRE).
US20020134685Dec 29, 1999Sep 26, 2002Kishore K. ChakravortyCoaxial capacitors are adapted to utilize the plating of a plated via as a first electrode, a dielectric layer formed to cover first electrode while leaving a portion of via unfilled, wherein second electrode is formed by a dielectric layer
US20030024389Jul 23, 2001Feb 6, 2003Flippo Belynda G.Method for carbon monoxide reduction during thermal/wet abatement of organic compounds
US20030041801Jan 23, 2001Mar 6, 2003Franz HehmannIndustrial vapor conveyance and deposition
US20030047070Dec 18, 2001Mar 13, 2003Flippo Belynda G.For retrofitting integrated scrubbers to provide maximum oxygen content in a controlled decomposition oxidation abatement procedure
US20030059720Jan 24, 2002Mar 27, 2003Hwang Jeng H.Masking methods and etching sequences for patterning electrodes of high density RAM capacitors
US20030064590Aug 7, 2002Apr 3, 2003Hwang Jeng H.Method of plasma etching platinum
US20030071255Oct 11, 2001Apr 17, 2003Daniel XuForming a trench using the tapered electrode as a mask for a self-aligned trench etch to electrically separate adjacent wordlines
US20030085111Feb 1, 2001May 8, 2003University Of Central FloridaFor mineralization and detoxification of gaseous and aqueous steams; improved coupling performance; comprises mercury vapor lamp
US20030098531Dec 10, 2002May 29, 2003Ebara CorporationMethod and apparatus of producing thin film of metal or metal compound
US20030132376Jan 17, 2003Jul 17, 2003The Trustees Of The University Of PennsylvaniaTip calibration standard and method for tip calibration
US20030168342Mar 12, 2003Sep 11, 2003Intel CorporationFor decoupling and power dampening applications to reduce signal and power noise and/or reduce power overshoot and droop in electronic devices
US20030222295May 27, 2003Dec 4, 2003Megic CorporationHigh performance system-on-chip inductor using post passivation process
US20040016948May 27, 2003Jan 29, 2004Megic CorporationHigh performance system-on-chip discrete components using post passivation process
US20040029404May 27, 2003Feb 12, 2004Megic CorporationHigh performance system-on-chip passive device using post passivation process
US20040032823Jun 26, 2002Feb 19, 2004Minoru KikuchiOptical disc and its manufacturing method
US20040037205Jun 19, 2003Feb 26, 2004Masataka ShinodaOptical recording medium and optical recording/reproducing method
US20040037206Oct 10, 2002Feb 26, 2004Masataka ShinodaOptical lens, condensing lens, optical pickup, and optical recording/reproducing device
US20040059455Sep 22, 2003Mar 25, 2004Konica Minolta Holdings, Inc.Manufacturing method of circuit substrate, circuit substrate and manufacturing device of circuit substrate
US20040077123Aug 8, 2003Apr 22, 2004Heon LeeLow heat loss and small contact area composite electrode for a phase change media memory device
US20040104417Nov 24, 2003Jun 3, 2004Samsung Electronics Co., Ltd.Ferroelectric memory device using via etch-stop layer and method for manufacturing the same
US20040105810Sep 11, 2003Jun 3, 2004Zhifen RenMetal oxide nanostructures with hierarchical morphology
US20040108596Dec 2, 2003Jun 10, 2004Intel CorporationSelectable decoupling capacitors for integrated circuit and methods of use
US20040110562Nov 25, 2003Jun 10, 2004Jiro KajinoTactile pin holding apparatus, tactile pin display apparatus and braille display member
US20040113084Feb 4, 2002Jun 17, 2004Josuke NakataRadiation detector and radiation detecting element
US20040114502Nov 25, 2003Jun 17, 2004Junichi TakahashiOptical-pickup slider, manufacturing method thereof, probe and manufacturing method thereof, and probe array and manufacturing method thereof
US20040130938 *Nov 5, 2003Jul 8, 2004Sharp Kabushiki KaishaSemiconductor memory device and control method thereof
US20040147047Nov 20, 2003Jul 29, 2004Cross Jeffrey ScottSemiconductor device and its manufacture method, and measurement fixture for the semiconductor device
US20040150043Feb 3, 2003Aug 5, 2004Motorola, Inc.Structure and method for fabricating semiconductor microresonator devices
US20040159828Sep 19, 2003Aug 19, 2004Unity Semiconductor, Inc.Resistive memory device with a treated interface
US20040159868Oct 8, 2003Aug 19, 2004Darrell RinersonConductive memory device with barrier electrodes
US20040159869Jan 26, 2004Aug 19, 2004Unity Semiconductor CorporationMemory array with high temperature wiring
US20040160804May 12, 2003Aug 19, 2004Unity Semiconductor CorporationMemory array of a non-volatile ram
US20040160805Dec 26, 2002Aug 19, 2004Unity Semiconductor CorporationMulti-output multiplexor
US20040160806Dec 26, 2002Aug 19, 2004Unity Semiconductor CorporationProviding a reference voltage to a cross point memory array
US20040160807Dec 26, 2002Aug 19, 2004Unity Semiconductor CorporationCross point memory array with memory plugs exhibiting a characteristic hysteresis
US20040160808Dec 26, 2002Aug 19, 2004Unity Semiconductor CorporationCross point memory array using distinct voltages
US20040160817May 12, 2003Aug 19, 2004Unity Semiconductor CorporationNon-volatile memory with a single transistor and resistive memory element
US20040160818Dec 26, 2002Aug 19, 2004Unity Semiconductor CorporationCross point memory array using multiple modes of operation
US20040160819Feb 7, 2003Aug 19, 2004Unity Semiconductor CorporationHigh-density NVRAM
US20040160820Jul 1, 2003Aug 19, 2004Darrell RinersonRe-writable memory with multiple memory layers
US20040160841Dec 26, 2002Aug 19, 2004Darrell RinersonMultiplexor having a reference voltage on unselected lines
US20040160846Jul 1, 2003Aug 19, 2004Darrell RinersonLine drivers that use minimal metal layers
US20040160847Jul 1, 2003Aug 19, 2004Darrell RinersonLayout of driver sets in a cross point memory array
US20040160848Jul 1, 2003Aug 19, 2004Darrell RinersonCross point memory array with fast access time
US20040160849Jul 1, 2003Aug 19, 2004Darrell RinersonLine drivers that fit within a specified line pitch
US20040161888Aug 4, 2003Aug 19, 2004Unity Semiconductor CorporationMulti-resistive state material that uses dopants
US20040170040Jul 30, 2003Sep 2, 2004Unity Semiconductor CorporationRewritable memory with non-linear memory element
US20040173837Mar 5, 2004Sep 9, 2004Agarwal Vishnu K.Multilayer electrode for a ferroelectric capacitor
US20040180453Mar 11, 2004Sep 16, 2004Samsung Electronics Co., Ltd.Ferroelectric memory device and method of forming the same
US20040180542Mar 13, 2003Sep 16, 2004Makoto NagashimaLow temperature deposition of complex metal oxides (CMO) memory materials for non-volatile memory integrated circuits
US20040183116Mar 30, 2004Sep 23, 2004Hag-Ju ChoIntegrated circuit devices having dielectric regions protected with multi-layer insulation structures and methods of fabricating same
US20040195613Apr 21, 2004Oct 7, 2004Hynix Semiconductor Inc.Semiconductor memory device capable of preventing oxidation of plug and method for fabricating the same
US20040201096Mar 30, 2004Oct 14, 2004Tomoo IijimaWiring circuit board, manufacturing method for the wiring circuit board, and circuit module
US20040201818Nov 27, 2002Oct 14, 2004Manabu YamamotoMethod for manufacturing pattern-forming body and pattern manufacturing apparatus
US20040219762May 24, 2004Nov 4, 2004Seiko Epson CorporationExfoliating method, transferring method of thin film device, and thin film device, thin film integrated circuit device, and liquid crystal display device produced by the same
US20040223786Apr 27, 2004Nov 11, 2004Canon Kabushiki KaishaImage forming apparatus
US20040232430Jun 29, 2004Nov 25, 2004Motorola, Inc.Structure and method for fabricating semiconductor structures and devices for detecting an object
US20040232431Jun 29, 2004Nov 25, 2004Motorola, Inc.Semiconductor structure and method for implementing cross-point switch functionality
US20040238942Jul 2, 2004Dec 2, 2004Intel CorporationElectronic assembly comprising ceramic/organic hybrid substrate with embedded capacitors and methods of manufacture
US20040240375Apr 16, 2004Dec 2, 2004Masataka ShinodaOptical recording medium and optical recording and reproducing method using this optical recording medium
US20040247815Mar 18, 2004Dec 9, 2004Nobuyuki TakamoriOptical information recording medium, recording and readout methods using the same, optical information recording device, and optical information readout device
US20040256697Aug 6, 2003Dec 23, 2004Wen-Yueh Jang[resistance random access memory and method for fabricating the same]
US20040257749Jun 8, 2004Dec 23, 2004Ngk Spark Plug Co., Ltd.Capacitor, capacitor equipped semiconductor device assembly, capacitor equipped circuit substrate assembly and electronic unit including semiconductor device, capacitor and circuit substrate
US20040264355Nov 14, 2003Dec 30, 2004Nobuyuki TakamoriOptical information recording medium, recording and reproduction methods using the same, optical information recording device, and optical information reproduction device
US20040266028Jun 24, 2003Dec 30, 2004Rodriguez John AnthonyMethod for improving retention reliability of ferroelectric ram
US20050013172Aug 17, 2004Jan 20, 2005Darrell RinersonMultiple modes of operation in a cross point array
US20050018516Aug 18, 2004Jan 27, 2005Christophe ChevallierDischarge of conductive array lines in fast memory
US20050029573Jun 29, 2004Feb 10, 2005Kabushiki Kaisha ToshibaNonvolatile semiconductor memory and manufacturing method for the same
US20050036939Aug 11, 2004Feb 17, 2005Stanislaus WongHydrothermal synthesis of perovskite nanotubes
US20050040481Sep 30, 2003Feb 24, 2005Kabushiki Kaisha ToshibaInsulating film and electronic device
US20050042836Sep 1, 2004Feb 24, 2005Samsung Electronics Co., Ltd.Capacitor for semiconductor device, manufacturing method thereof, and electronic device employing the same
US20050045933Aug 10, 2004Mar 3, 2005Shinichiro KimuraSemiconductor memory device and manufacturing method thereof
US20050051870Dec 22, 2003Mar 10, 2005Semiconductor Energy Laboratory Co., Ltd.Semiconductor device and a method of manufacturing the same
US20050059208Nov 4, 2004Mar 17, 2005Clampitt Darwin A.Spacer patterned, high dielectric constant capacitor
US20050066993Aug 26, 2004Mar 31, 2005Kazuhide HasebeThin film forming apparatus and method of cleaning the same
US20050082726May 28, 2002Apr 21, 2005Advanced Ceramics Research IncCeramic components having multilayered architectures and processes for manufacturing the same
US20050101714Sep 28, 2004May 12, 2005Nippon Shokubai Co., Ltd.A dispersion of an inorganic dielectric in a fluorinated aromatic polymer with excellent dispersibility and high dielectric constant
US20050105038Dec 22, 2004May 19, 2005Fujitsu LimitedThin film multilayer body, electronic device and actuator using the thin film multilayer body, and method of manufacturing the actuator
US20050106839Dec 16, 2004May 19, 2005Seiko Epson CorporationTransfer method, method of manufacturing thin film devices, method of maufacturing integrated circuits, circuit board and manufacturing method thereof, electro-optical apparatus and manufacturing method thereof, IC card, and electronic appliance
US20050111263Dec 13, 2004May 26, 2005Unity Semiconductor CorporationCross point array using distinct voltages
US20050121240Jun 18, 2004Jun 9, 2005Aase Jan H.Airflow control devices based on active materials
US20050127403Jan 5, 2005Jun 16, 2005Sharp Laboratories Of America, Inc.RRAM circuit with temperature compensation
US20050128840Jan 31, 2005Jun 16, 2005Darrell RinersonCross point memory array exhibiting a characteristic hysteresis
US20050167699Feb 22, 2005Aug 4, 2005Matsushita Electric Industrial Co., Ltd.Variable resistance element, method of manufacturing the element, memory containing the element, and method of driving the memory
US20050180189Feb 16, 2005Aug 18, 2005Infineon Technologies AgMemory device electrode with a surface structure
US20060002174Jun 28, 2005Jan 5, 2006Sharp Kabushiki KaishaDriving method of variable resistance element and memory device
US20060006471Jul 8, 2005Jan 12, 2006International Business Machines CorporationResistor with improved switchable resistance and non-volatile memory device
US20060027893Jul 7, 2005Feb 9, 2006International Business Machines CorporationField-enhanced programmable resistance memory cell
US20060131556 *Dec 22, 2004Jun 22, 2006Micron Technology, Inc.Small electrode for resistance variable devices
Non-Patent Citations
Reference
1A. Beck, J.G. Bedmorz, CH. Gerber, C. Rossel and D. Widmer, Reproducible Switching Effect in This Oxide Films for Memory Applications, Applied Physics Letters, Jul. 3, 2000, vol. 77, No. 1, pp. 139-141.
2C. Rossel, G.I. Meijer, D. Bremaud, and D. Widmer, Electrical Current Distribution Across a Metal-Insulator-Metal Structure During Bistable Switching, Journal of Applied Physics, Sep. 15, 2001, vol. 90, No. 1, pp. 2892-2898.
3M.J. Rozenberg, I.H. Inoue, and M.J. Sanchez, Nonvolatile Memory With Multilevel Switching: A Basic Model, Physical Review Letters, Week Ending Apr. 30, 2004, vol. 92, No. 17, pp. 178302-1-178302-4.
Classifications
U.S. Classification438/102, 365/163, 257/5, 257/E29.002, 257/3, 257/4, 257/2, 438/103
International ClassificationH01L29/02
Cooperative ClassificationH01L45/1273, H01L45/1683, H01L45/04, H01L45/1233, H01L45/146, H01L45/147
European ClassificationH01L45/14C